Lathe with log-supporting mechanism



Feb. 26, 1963 E. M. HETH 3,073,337

' LATHE WITH'LOG-SUPPORTING MECHANISM Filed March 7, 1961 2 Sheets-Sheet1 Edwin M.H 'l'h INVENTOR.

Feb. 26, 1963 Filed March 7, 1961 E. M. HETH LATHE WITH LOG-SUPPORTINGMECHANISM 2 Sheets-Sheet 2 m Edwin M.Hefh 3 [A INVENTOR. Q

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United States Patent Office 3,fi78,887 Patented Feb. 26, 1963 $378,887LATER WITH LUG- UPPURTING MECHANESM Edwin M. l-leth, Portland, Greg,assignor to Premier Gear & Machine Works, lno, Portland, reg., acorporation of Oregon Fiied Mar. 7, 1961, Ser. No. 93,922 12 Claims.(Ci. 144-209) This invention relates to veneer lathes, and moreparticularly to a lathe that includes means for supporting intermediateportions of a log during the cutting of veneer therefrom, whereby bettercut veneer results and the log can be reduced to the smallest possiblecore.

The usual veneer lathe has a pair of pedestals mounting spaced-apart andopposed chucks that hold the ends of the log during the cutting ofveneer therefrom. Typically a carriage is provided the lathe, andmounting a knife and pressure bar, is advanced toward the log, with theknife cutting veneer and with the pressure bar exerting a pressure onand steadying the log during cutting. The knife and bar exert forces onthe log intermediate where its ends are held by the lathe chucks, andconsequently there is a tendency for the middle part of the log to bepushed outwardly from alignment with the chuck centers, particularlyevident when the log is peeled down to a relatively small core. Tocorrect these tendencies, it has been suggested that some kind ofsupport or steady rest be provided the log, operable to counteract thesedislocating forces that otherwise cause the log to bow outwardly.

Generally, it is an object of this invention to provide improved meansfor steadying or supporting portions of a log extending between thechucks of a lathe during the cutting of veneer therefrom.

In the typical lathe, the knife and pressure bar are disposed at aheight that approximately corresponds to the elevation of the centeraxes of the chucks. The knife and bar are advanced inwardly on a log,from a position they have to one side of the chucks, and the log isrotated so that its surface is moving down on the knife during cutting.As a result, forces are exerted on the log that have a directionextending upwardly and toward the side of the chucks opposite the sidewhere the knife is disposed. Steadying means for a log preferably shouldbe such that a substantially uniform amount of support be provided thelog, regardless of variations in diameter. To enable most simply thatsuch support be provided a log, and included in the objects of thisinvention, this invention contemplates the provision of supportmechanism that moves inwardly on a log, as veneer is removed and thelogs diameter becomes smaller, along substantially a straight path, suchpath approximately coinciding with the direction of the forces exertedon the log by the action of the knife. Regardless of log diameter, thesupport mechanism exerts a total force on the log that extends in adirection approximately opposite to the direction of the total forceexerted on the log by the action of the knife and pressure bar.

Another factor to be considered in the construction of a lathe, is theease with which a core may be removed from the lathe after all veneerhas been cut therefrom, and a new log substituted for the core removed.Maximum production is possible if this substitution of a new log is madeas speedily as possible. To facilitate removal of a core, it issometimes advantageous, after loosening of the chucks, to extend themeans used for steadying the core, so that it performs the additionalfunction of pushing the core out from between the chucks. After this,the steadying means should be retracted swiftly, to clear quickly thespace between the chucks for a new log. Accordingly, it is anotherobject of this invention to provide an improved construction for supportor steadying means or mechanism of the type contemplated, that may beactuated so as to assist in the removal of a final core, and thencleared rapidly from between the chucks of a lathe to free the lathe forthe reception of a new log.

In a more specific sense, it is an object of this invention to provide alathe which includes, as support mechanism for a log, an elongatedextensible-retractable arm, mounted for pivotal movement about an axisparalleling and above the axes of the chucks of the lathe, such axisbeing on the side of the lathe opposite the side on which the knife androller bar are disposed. The arm is swingable from a raised positionwhere its free or nonpivoted end is above the lathe, to a loweredposition where the free end thereof is adjacent the periphery of a log.The extensible-retractable arm has means provided its nonpivoted end forcontacting a log and exerting a pressure thereon, such pressure beingexerted during lathe operation in a direction coinciding with thedirection in which the arm is extensible.

Another object is to provide a lathe with such an arm for providingsupport, wherein power-operated means is provided for swinging the armbetween raised and lowered positions, and the arm has a pivot axis solocated that the free end of the arm, in moving toward a raisedposition, moves in a direction toward and then over the knife, so thatthe space between the lathe chucks is immediately cleared for the supplyof a new log to a lathe.

Another object is to provide a lathe with steadying mechanism for a log,where such mechanism comprises an elongated arm, and a pair ofpower-operated means for placing the end of the arm in an inoperative,out of the way position, one of these power-operated means beingeffective to swing the arm in an arc upwardly and the other beingeffective to withdraw the end backwardly along the length of the arm.

Still a further object is to provide a novel construction for anextensible-retractable arm, used as steadying mech anism in a lathe,where the arm is well suited to withstand the stresses and strains itnormally is subjected to during the peeling of veneer from a log.

These and other objects and advantages will become more apparent, as thefollowing description is read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a view of the back of a lathe, such lathe being provided withlog steadying mechanism constructed according to one embodiment of thisinvention;

FIG. 2 is a view of one side of the lathe shown in FIG. 1, with portionsremoved therefrom;

FIG. 3 is a view, somewhat enlarged and with portions removed, of anelongated extensible-retractable arm present in the construction; and

PEG. 4 is an enlarged, cross-sectional view, taken along the line 44 inFIG. 3.

Referring now to the drawings, at 10 there is indicated generally alathe, such lathe having a base frame 12 and mounted on frame 12 andspaced from each other a pair of opposed pedestals 14, 16. Projectinginwardly from pedestals 14, 16 are opposed and spaced-apart chucks 18,20, such chucks typically having center axes that are aligned andhorizontally disposed. The location of these axes is indicated in FIG. 2at 17. The usual mechanism (not described as it forms no part of theinvention) is provided for moving the chucks toward and away from eachother, to hold and to release a log, respectively. Power-operated means(not shown) is provided for rotating the chucks, whereby a log held bythe chucks is rotated about an axis coinciding with the aligned centeraxes of the chucks, such axis therefor also being designated at 17 inFIG. 2 (during operation of the lathe, the log is rotated in a clockwisedirection in FIG. 2).

Lathe 10 includes a carriage shown in outline at 28',

that is movable to and fro between the pedestals by means of feed screwssuch as feed screw 30, thus to position a log supported on chucks 18, 20relative to the carriage. Mounted on the carriage, and indicated at 32,34, respectively, are the usual knife and pressure bar. The knife andpressure bar substantially parallel a log on the lathe and arepositioned approximately at the height of the center axes of the chucks.As the outside of a log revolves against the knife and bar, a sheet ofveneer is produced, with the log progressively getting smaller indiameter as veneer is removed.

As so far described, the lathe is conventional, and thus it has not beendescribed in too great detail. In general terms, it may be said that thelathe is typified by a knife and pressure bar disposed to one side andat approximately the height of the center axes of the chucks, that areadvanced into the outside of a log, with the logs surface movingdownwardly on the knife and bar, to produce a sheet of veneer.

During the cutting of veneer, because of the pressure exerted by theknife and bar on the log and because of the downward movement of the logsurface on the knife, a force is exerted on the log which extendsgenerally upwardly and to the left, viewing the lathe as in FIG. 2. Suchforce tends to produce bowing in the log, particularly when it has beenreduced to a core of relatively small diameter. To inhibit such bowingtendencies, a support or steady rest mechanism for the log is provided,indicated generally at 40, which is used to brace the log between itsends.

Specifically, 42 indicates an elevated frame, supported above the floorby legs 44. The frame is above the chucks, and extends to the left ofchucks, viewing the lathe as in FIG. 2. The elevated position of theframe enables new logs to be supplied the lathe, moving the logs in fromthe left in FIG. 2, without encumbrance by the frame.

Frame 42 includes an elongated beam 46 that substantially parallels alog in the lathe, and extends between the lathe pedestals. Disposedabove chucks 18, 20 and substantially midway between them, and pivotallyconnected to beam 46, by pivot means 48, is an elongatedextensibleretractable mechanism or arm 52. Pivot means 48 is above andto the left of the chucks in FIG. 2, which enables mechanism 52 to beswung from the inoperative position shown in solid outline in FIG. 2,downwardly with its nonpivoted or free end moving in an are as indicatedby the arrows in FIG. 2. In its lowered position, shown in dashedoutline in FIG. 2, the free end of arm 52, pivot means 48, and axis 17are in substantial alignment. The arm in its lowered position extendsupwardly from a log in a direction substantially coinciding with thedirection of the forces exerted on a log by knife 32 and the bar duringcutting by the knife.

Arm 52 comprises a pair of rigid, telescopic sections 58, 60, each ofwhich has a substantially rectangular cross section, as can be seen withreference to FIG. 4. Inner section 60 is slidably received within outersection 58. The sections are extensible and retractable with respect toeach other, and are shown in their relatively contracted position inFIG. 3.

Various forms of constructions may be used for sections 58, 60. In theembodiment illustrated, the outer section has topand bottom walls 61, 62and opposed side walls 63, 64 forming an enclosed box-like structure,closed at its left end in FIGS. 2 and 3 by end wall 65. Inner section 60comprises opposed, approximately channelshaped members 67, 68, heldtogether by end plates 70, 71 and intermediate plate 72 (see FIG. 3).

Secured to the outside of and extending forwardly from inner section 60,and part of the section, are plates 80 (the plate 80 on the rear side ofsection 60 is obscured in FIGS. 2 and 3). Pivotally mounted on theseplates, by pivot connections 86, are mounting plates 84. The mountingplates 84 extend forwardly of the pivot connections 86, and have rollers82, 83 journaled thereon. Pivotal movement of the plates is limited bystops 88 projecting inwardly from plates 80. The rollers in an operativeposition for arm 52, as can be seen with reference to the dashed outlineof the arm in FIG. 2, rotate about axes that parallel a log being cut,and constitute the means in the mechanism actually contacting a log whenthe same is being steadied.

Extension of the sections, and retraction, is produced by afluid-operated jack or ram, indicated at 100, disposed within sections58, 60, so that the ram is protected by the sections. The cylinder endof ram is pivotally connected to end wall 65 of outer section 58,whereas the rod end is pivotally connected to plate 72 of inner section60. End plate 70 of section 60 has an aperture 102 formed therein whichaccommodates the connection of ram 100 with end wall 65.

Means is provided for swinging the arm between the raised position shownin solid outline in FIG. 2 and the lowered position indicated in dashedoutline. Thus, a ram or jack 110, is included, that has its rod endconnected by pivot connection 112 to outer section 58, and its cylinderend connected by pivot connection 114 to a beam 116 which is part ofelevated frame 42.

Explaining now the operation of the apparatus described, with the armraised and in its inoperative position, it is out of the way of thespace between the chucks, which enables a log to be supplied the latheand properly positioned on the chucks. During cutting of veneer, andbefore the log is reduced to a core of small diameter, ram and ram 100may be actuated, causing the arm to swing to its lower position and toextend, to place rollers 82, 83 in rolling contact with the periphery ofthe log. In such position, the rollers function to support the log, byexerting a force on the log that counteracts forces exerted on the logby the knife and roller bar. When cutting of veneer is finished, thelathe chucks may be retracted, and ram 100 may be extended to its fullextent, to assist in freeing the core remaining from the chucks. Arm 52may then be quickly moved out of the way, by simultaneous retraction oframs 100, 110, with the free end of the arm retracting and also swingingupwardly.

It will be noted that the construction has several advantages. The armis extensible along a straight path that approximately coincides withthe direction of the forces exerted on the log by the knife and pressurebar. This facilitates the application of a steady, even pressure on thelog. It should be noted also that since the arm is swung toward theknife and upwardly in moving to a retracted position, there is almostimmediate clearance of the space between the chucks of the lathe afterthe removal of the core. This is so, even if the mechanism is reliedupon to assist in clearing the lathe. Note also that both retraction ofthe arm and swinging of the arm can be utilized in clearing the spacebetween the lathe chucks.

The telescopic sections have the requisite rigidity to withstand shocksand stresses imparted thereto. They are easily shifted to a fullyextended position. The ram producing extension and retraction of thesections is fully protected from stresses by the telescopic sectionsthat encompass it.

I claim:

1. In a veneer lathe having opposed spaced-apart chuck-s for holding theends of a log and rotating it about a rotation axis extending betweenthe chucks, and a knife extending between and positioned laterally toone side of the chucks for cutting a sheet of veneer from the log,support means for the log comprising elongated power-operated lineallyextensible mechanism positioned intermediate the ends of the knife andlaterally to the other side of said chucks from said kuife, meansdisposed on said other side of said chucks and above the chuckspivotally mounting one end of said mechanism and accommodating pivotalmovement of the mechanism about an axis substantially paralleling saidrotation axis, the end of said mechanism opposite said one end beingswingable in an are from a raised position disposed above ,the

chucks downwardly to a position where said opposite end is adjacent saidrotation axis, means provided said opposite end of the mechanism forcontacting the, log

.and operable to exert. a pressure against the log, and

power-operated means connected to said extensible mechanism for swingingit in said arc.

2. In a veneer lathe having opposed spaced-apart chucks for holding theends of a log and rotating it about :a rotation axis extendingbetween'the chucks, and a tensible armincluding means for extending saidarm, pivot means disposed above the chucks pivotally mounting one end ofsaid arm with the arm depending from the pivotmeans and in aposition'where the end opposite said one. end may swing'in an'arc towardand then above said knife on pivotal movement of the arm, means on said.opposite end of said arm for contacting a log and operable to exert apressure on the, log, and power-operatedmeans'connected to said arm forswinging it in said arc.

3. In a veneer lathe having opposed spaced-apart chucks for holding theends of a log and rotating it about a rotation axis extending betweenthe. chucks, and a knife extending between and positioned laterally toone side of the chucks for cutting a sheet of veneer from a log, meansfor supporting the log at a location intermediate its ends, said meanscomprising an elongated arm having a pair of rigid sections, one formingone end and one forming the other end of said arm, said sections beingmounted with one section slidable relative to the other whereby the armis extensible and retractable, a fluid-operated ram mounted on said armwith one end secured to one of said sections and its opposite endsecured to the other of said sections and operable on actuation toproduce extension and retraction of the arm, pivot means disposed abovethe chucks pivotally mounting the section forming one end of the armwith said arm depending from said pivot means and in a position wherethe end of the arm opposite said one end may swing in an arc toward andthen above said knife on pivotal movement of the arm, means on saidopposite end of said arm for contacting a log and operable to exert apressure on the log, and power-operated means connected to said arm forswinging it in said arc.

4. In a veneer lathe having opposed spaced-apart chucks for holding theends of a log and rotating it about a rotation axis extending betweenthe chucks, and a knife extending between and positioned laterally toone side of the chucks for cutting a sheet of veneer from the log, meansfor supporting the log at a location intermediate its ends, said meanscomprising an elevated frame disposed above and to the other side ofsaid chucks from said knife, an elongated arm having a pair of rigidsections, one forming one end and one forming the other end of said arm,said sections being mounted with one slidable relative to the otherwhereby the arm is extensible and retractable, a fluid-operated rammounted on said arm with one end secured to one of said sections and itsopposite end secured to the other of said section and operable onactuation to produce extension and retraction of the arm, pivot meansdisposed above the chucks pivotally mounting the section forming one endof the arm with said arm depending from said pivot means and in aposition where the end opposite said one end may swing in an arc towardand then above said knife on pivotal movement of the arm, means on saidopposite end of said arm for contacting a log and operable to exert apressure on the log, and poweroperated means connected to said arm forswinging it in said arc, said power-operated means comprising a fluid- 6operated ram pivotally connected at'oneend to said arm and pivotallyconnected at its other end to said support. 5. In a veneer lathe havingopposed spaced-apart chucks for holding the ends of a log and rotatingit about arotation axis-extending between the chucks, and a'knifeextending between and positioned laterally to one side of the chucks forcutting a sheet of veneer from the log, support means for the logcomprising elongated power-operated extensible-retractable mechanismpositioned intermediate the ends of the knife and laterally to the otherside of said chucks from said knife, said mechanism comprising a pairofrigid sectionswith one mounted on the other and slidable relative tothe other to produce extension and retraction of the mechanism, anda-fluidoperated ram mounted'with one end connected to one of saidsections and the other end connected to the other of said sectionsoperable on' actuation to produce extendownwardly to a-position-wheresaid opposite end is adjacent said rotation axis, means provided saidopposite end of said mechanism for contacting the log and operable toexert a pressure against'theflog, and power-operated means connected tosaid'mechanism for swinging it in said are.

6.*The lathe 0f'claim5 wherein an elevated frame'is provided above saidchucks and wherein the power-operated means for swinging the mechanismin said are comprises a fluid-operated ram pivotally connected at one ofits ends to one of said sections at the other of its ends to saidelevated frame.

7. In a veneer lathe having opposed spaced-apart chucks for gripping theends of a log and for rotating it about an axis extending between thechucks, and a knife extending between and positioned laterally to oneside of the chucks for cutting a sheet of veneer from the log, anelevated frame supported above said chucks and to the other side of saidchucks from said knife, an elongated lineally extensible arm, meanspivoting one end of said arm on said elevated frame at a locationdisposed above said chucks and on said other side of said chucks, saidarm having an end opposite said one end that is swingable in an arebetween a raised position above said chucks and a lowered position wheresaid opposite end and said one end are substantially aligned with thelog rotation axis, power-operated means mounted on said arm forproducing extension and retraction thereof, means on said other end ofsaid arm for engaging a log and exerting a pressure thereon, andpower-operated means interposed between said arm and said elevated framefor swinging said arm between its raised and lowered positions.

8. In a veneer lathe having opposed spaced-apart chucks for gripping theends of a log and for rotating it about an axis extending between thechucks, and a knife extending between and positioned laterally to oneside of the chucks for cutting a sheet of veneer from the log, anelevated frame supported above said chucks and to the other side of saidchucks from said knife, an elongated extensible-retractable arm, saidarm being formed of a pair of hollow telescopic sections, one receivedwithin the other, with the sections extensible and retractable relativeto each other, means pivoting one end of said arm by pivotally mountingone of the sections on said elevated frame and at a location disposedabove said chucks and on said other side of said chucks, said arm havingan end opposite said one end that is provided by said other section andis swingable in an are between a raised position above said chuck and alowered position where said opposite end and said one end are of the armsubstantially aligned with the rotation axis of the log, a ram disposedwithin said telescopic sections and shielded thereby, means connectingone end of said ram to one of said sections and the other end of the ramto the other of said sections whereby actuation of the ram producesextension and retraction of the arm, means on said opposite end of saidarm for engaging a log and exerting a pressure thereon, andpower-operated means interposed between said arm and said elevated framefor swinging said arm between its raised and lowered positions.

9. The lathe of claim 8 wherein the means for swinging said armcomprises a fluid-operated ram with a cylinder end pivotally connectedto said elevated frame and a rod end pivotally connected to one of saidtelescopic sections.

10. The lathe of claim 8 wherein the means for contacting a logcomprises a pair of rolls spaced one from the other and substantiallyparalleling said rotation axis, and a mounting for the rolls pivotallymounted on said other section.

11. In a veneer lathe having opposed spaced-apart chucks for holding theends of a log and rotating it about a rotation axis extending betweenthe chucks, and a cutting assembly extending between the chucks andpositioned laterally to one side of said axis, means for supporting alog in the lathe comprising an elongated arm, means pivotally mountingone end of said arm at a point spaced laterally toward the opposite sideof said rotation axis from said one side, said arm having an endopposite said one end that is lineally extensible from said one end,power-operated means for producing extension of said opposite end ofsaid arm from said one end, and means on said opposite end of said armfor contacting the log and operable to exert a force on the log, saidopposite end of said arm with the arm in operative position andsupporting a log being extensible in a direction substantially oppositeto the direction of the total force exerted on the log by the cuttingassembly of the lathe.

12. In a veneer lathe having opposed spaced-apart chucks for holding theends of a log and rotating it about a rotation axis extending betweenthe chucks, and a cutting assembly extending between the chucks and p0sitioned laterally to one side of said axis, means for sup porting a login the lathe comprising an elongated arm positioned laterally to theother side of said rotation axis from said cutting assembly, meansmounting said arm with the arm projecting out from its mounting towardsaid rotation axis in a direction substantially opposite to thedirection of the total force exerted on a log by the cutting assembly ofthe lathe, said arm terminating in an end adjacent said rotation axisthat is extensible lineally in the same direction that the arm projectsfrom its mounting, means on said end for contacting a log and exerting aforce thereon, and power-operated means for producing extension of saidarm.

References Cited in the file of this patent UNITED STATES PATENTS2,884,966 Zilm May 5, 1959

2. IN A VENEER LATHE HAVING OPPOSED SPACED-APART CHUCKS FOR HOLDING THEENDS OF A LOG AND ROTATING IT ABOUT A ROTATION AXIS EXTENDING BETWEENTHE CHUCKS, AND A KNIFE EXTENDING BETWEEN AND POSITIONED LATERALLY TOONE SIDE OF THE CHUCKS FOR CUTTING A SHEET OF VENEER FROM THE LOG, MEANSFOR SUPPORTING THE LOG AT A LOCATION INTERMEDIATE ITS ENDS COMPRISING ANELONGATED LINEALLY EXTENSIBLE ARM INCLUDING MEANS FOR EXTENDING SAIDARM, PIVOT MEANS DISPOSED ABOVE THE CHUCKS PIVOTALLY MOUNTING ONE END OFSAID ARM WITH THE ARM DEPENDING FROM THE PIVOT MEANS AND IN A POSITIONWHERE THE END OPPOSITE SAID ONE END MAY SWING IN AN ARC TOWARD AND THENABOVE SAID KNIFE ON PIVOTAL MOVEMENT OF THE ARM, MEANS ON SAID OPPOSITEEND OF SAID ARM FOR CONTACTING A LOG AND OPERABLE TO EXERT A PRESSURE ONTHE LOG, AND POWER-OPERATED MEANS CONNECTED TO SAID ARM FOR SWINGING ITIN SAID ARC.